1. Field of the Invention
This invention relates to an intruder detection device for deciding the occurrence of an invasion if an electric wave, which is received by a leakage transfer passage on the receiving side juxtaposed to a leakage transfer passage on the transmitting side for receiving a leakage electric wave from said transmitting leakage transfer passage, changes.
This intruder detection device is suitably used in case the presence/absence of an intruder and the position of invasion are detected over a relatively wide range such as in a factory, a substation, an airport or a parking zone.
2. Description of the Related Art
An intruder detection system of a related art employs a monitor camera, for example. In this system, for example, a plurality of monitor cameras are employed to detect the location of an intruder (as referred to JP-A-9-172630 (Patent Publication 1)).
In this intruder detection system for detecting the position of an intruder by using the plural monitor cameras, the detection range/time has to be set by changing the positions of the monitor cameras, the positions of images or the monitor camera themselves, thereby to raise problems of a poor precision for setting the detection range and a complicated setting method. In order to perform detections over a long distance and of a monitor area of a complicated structure and a wide shape, a number of monitor cameras are needed to mismatch a large-scale intruder detection system for detecting an intruder in the factory, substation or airport.
In recent years, on the other hand, an obstacle detection device, as described in JP-A-2004-306909 (Patent Publication 2), for example, is proposed as one of the intruder detection device which does not employ the plural monitor cameras.
FIG. 14 is a block diagram showing the configuration of the obstacle detection device of a related art, as described in Patent Publication 2, for example. In FIG. 14, three reference spectrum diffusion signal generating means 9-1 to 9-3 generate the reference diffusion codes of the delay times, which correspond to the obstacle measurement distances of 0 to 30 m and the detection precision of ±5 m, from a reference clock signal, and output reference spectrum diffusion signals which have been diffused and modulated with the reference diffusion codes. A plurality of correlating means 10-1 to 10-3 corresponding to the reference spectrum diffusion signal generating means 9-1 to 9-3 correlate the transmitted spectrum diffusion signals received by a receiving leakage transfer passage 6 and the reference spectrum diffusion signals, and output a correlation signal when their phases are identical. When the fluctuations of the signal level of the correlation signal from the individual delay times are at a set value or more, detection means 11 detects that an obstacle has invaded into the side.
On the other hand, FIG. 15 is a diagram showing the number of obstacle detection devices 12 of the prior art installed supposing the case, in which the obstacle detection devices 12 described in Patent Publication 2 are made to cover the surrounding of 3,000 m of a factory 13 needed by the customer. In FIG. 15, one obstacle detection device 12 has a detection range of 30 m, so that one hundred obstacle detection devices 12 are used for the case of the detection range of 3,000 m.
[Patent Publication 1]
JP-A-9-172630 (FIG. 1 and its Description)
[Patent Publication 2]
JP-A-2004-306909 (FIG. 1 and its Description)
Since the obstacle detection device of the related art, as disclosed in Patent Publication 2, is configured, as described above, a plurality of obstacle detection devices have to be installed in case the detection range is enlarged. In case a plurality of correlating means are to be mounted on one obstacle detection device, there arises problems against commercialization, such as a complicated ratio H/W or an easy susceptibleness to influences of heat liberation or noises thereby to make it difficult to improve the detection precision.